/**

    Let inheritance help with memory efficiency

*/

function SignalFire(ID, startingLogs){

    this.fireID = ID;

    this.logsLeft = startingLogs;

}

SignalFire.prototype = {

    addLogs: function(numLogs){

        this.logsLeft += numLogs;

    }

    lightFire: function(){

        alert("Whooosh!");

    }

    smokeSignal: function(message){

        if(this.logsLeft < this.message.length / 10){

            alert("Not enough");

        }else{

            this.lightFire();

            var x = this.message.length;

            for(var i = 0; i < x; i++){

                alert("((("+this.message[i]+")))");

                if(i % 10 == 0 && i != 0){

                    this.logsLeft--;

                }

            }

        }

    }

}

var fireOne = new SignalFire(1, 20);

var fireTwo = new SignalFire(2, 18);

var fireThree = new SignalFire(3, 14);

fireOne.addLogs(8);

fireTwo.addLogs(10);

fireThree.addLogs(14);

fireThree.smokeSignal("Goblins!");

//The addLogs method is found in one useful place, instead of being

//replicated across all signalFires.

/**

    Adding individual dom elements ain't always speedy

*/

//

//**BAD**

//

var list = document.getElementById("kotwList");

var kotw = ["Jenna Rangespike",

            "Neric Farthing",

            "Darkin Stonefield"];

for(var i = 0, x = kotw.length; i < x; i++){

    var element = document.creatElement('li');

    element.appendChild(document.createTextNode(kotw[i]));

    list.appendChild(element);

}

//appendChild(); function each time this list is appened, we access the DOM

//and cause an entire document reflow. Not as speedy as we'd like, especially

//if we list was huge...

/*

    Improve: Use a document fragment to insert additions all at once

*/

var list = document.getElementById("kotwList");

var kotw = ["Jenna Rangespike",

            "Neric Farthing",

            "Darkin Stonefield"];

var fragment = document.createDocumentFragment();

for(var i = 0, x = kotw.length; i < x; i++){

    var element = document.creatElement('li');

    element.appendChild(document.createTextNode(kotw[i]));

    fragment.appendChild(element);

}

list.appendChild(fragment);

/*

    Improve: declare variables as few times as possible

*/

//

//**GOOD**

//

var list         = document.getElementById("kotwList"),

    kotw         = ["Jenna Rangespike",

                    "Neric Farthing",

                    "Darkin Stonefield"],

    fragment     = document.createDocumentFragment(),

    element;

for(var i = 0, x = kotw.length; i < x; i++){

    element = document.creatElement('li');

    element.appendChild(document.createTextNode(kotw[i]));

    fragment.appendChild(element);

}

list.appendChild(fragment);

/**

    Efficient choices for string concatenation

*/

//

//**OK**

//

var knight = "Jenna Rangespike",

    action = " strikes the dragon with a ",

    weapon = "Halberd",

    turn = "";

turn += knight;

turn += action;

turn += weapon;

//It is ok because the code is short and clear

//

//**NOT GOOD ENOGUTH

//

var newPageBuild = ["<!DOCTYPE html>", "<html>", "<body>", "<h1>",

                    *** a hundred or more other html elements***,

                    "</script>", "</body>", "</html>"],

     page = "";

for(var i = 0, x = newPageBuild.length; i < x; i++){

    page += newPageBuild[i];

}

//

//**GOOD**

//

page = newPageBuild.join("\n");

//Using join is much faster than using '+=' and looks simple and clear!!

[Javascript]3. Improve you speed! Performance Tips的更多相关文章

  1. [Javascript]1. Improve you speed! Loop optimaztion

    /** Improve you loop code */ var treasureChest = { goldCoins: 10000, magicalItem : "Crown of Sp ...

  2. [Javascript]2. Improve you speed! Script Execution

    Let's take a closer look at how a browser retrieves and acts on scripts.modern browser can parallel ...

  3. Android 性能优化（19）＊代码优化11条技巧：Performance Tips

    Performance Tips 1.In this document Avoid Creating Unnecessary Objects 避免多余的对象 Prefer Static Over Vi ...

  4. 转载：Why using Single Root I/O Virtualization (SR-IOV) can help improve I/O performance and Reduce Costs

    Introduction While server virtualization is being widely deployed in an effort to reduce costs and o ...

  5. SQL Server performance tips

    Refer to: http://harriyott.com/2006/01/sql-server-performance-tips A colleague of mine has been look ...

  6. How To Improve Deep Learning Performance

    如何提高深度学习性能 20 Tips, Tricks and Techniques That You Can Use ToFight Overfitting and Get Better Genera ...

  7. 翻译--Blazing fast node.js: 10 performance tips from LinkedIn Mobile

    1.避免使用同步代码: // Good: write files asynchronously fs.writeFile('message.txt', 'Hello Node', function ( ...

  8. Performance tips

    HTML5 Techniques for Optimizing Mobile Performance Scrolling Performance layout-performance

  9. Json.NET Performance Tips

    原文: http://www.newtonsoft.com/json/help/html/Performance.htm To keep an application consistently fas ...

随机推荐

  1. LVM管理

    一.步骤: 1.创建新的分区,并修改分区类型为8e 2.创建物理卷PV 3.将新建的PV添加到要扩展的VG中 4.用命令lvextend或lvresize来将新加入的PE添加到要扩展的LV中 5.用命 ...

  2. html img Src base64 图片显示

    http://blog.csdn.net/knxw0001/article/details/10983605 大家可能注意到了,网页上有些图片的src或css背景图片的url后面跟了一大串字符,比如: ...

  3. [ASP.NET] 檔案讀寫權限問題

    今天遇到一個問題,環境如下: IIS Server: Server 2008 R2 沒加域 File Server: Server 2003 加域 當我的Web程序需要把位於File Server的一 ...

  4. WebApi2官网学习记录--HttpClient Message Handlers

    在客户端,HttpClient使用message handle处理request.默认的handler是HttpClientHandler,用来发送请求和获取response从服务端.可以在clien ...

  5. CocoaPod安装

    http://www.360doc.com/content/14/0309/10/11029609_358970353.shtml http://www.bubuko.com/infodetail-4 ...

  6. js实现楼层效果

    今天自己写个楼层效果,有一点烦躁,小地方犯错误.各位大神来修改不足啊!!! <!DOCTYPE html><html lang="en"><head& ...

  7. javascript取消disabled属性

    jQuery: $("#ID").attr("disabled",false);

  8. ViewDragHelper的使用

    一.ViewDragHelper的原理 是一个能够自用移动ViewGroup内部View的控件. 通过获取ViewGroup的点击事件,之后通过Scroller滑动来进行对ViewGroup内部控件的 ...

  9. 函数:Python的乐高积木 - 零基础入门学习Python017

    函数:Python的乐高积木 让编程改变世界 Change the world by program 相信大家小时候应该都玩过神奇的乐高积木,只要通过想象和创意,我们可以用它拼凑出很多神奇的东西. 随 ...

  10. C语言一维指针的深入理解

    指针是C语言中广泛使用的一种数据类型.运用指针编程是C语言最主要的风格之一. 利用指针变量可以表示各种数据结构:能很方便地使用数组和字符串:并能象汇编语言一样处理内存地址,从而编出精练而高效的程序.指 ...